She's named after a Greek goddess and stands astride a $50bn sales colossus but Irene Rosenfeld, the boss of Kraft Foods and new owner of Cadbury, is nowhere to be seen.

Whispers started in the anxious days that followed the Cadbury board's capitulation to an £11.9bn offer from the maker of Ritz crackers and Dairylea. When would the American businesswoman, ranked sixth in Forbes magazine's female global power list, pitch up at the company's home in Bournvillle and tell them what the future holds for the 186-year-old company?

The chorus grew louder when Rosenfeld broke her first promise to the Cadbury workers she had welcomed to the "Kraft Foods family" just days earlier by announcing that she planned to close its Somerdale plant in Somerset after all.

There will also be an Irene-shaped hole at Tuesday's meeting of the House of Commons select committee which is looking at takeover rules in the wake the buyout. Kraft says she cannot attend due to "other engagements" but Unite deputy general secretary Jack Dromey, who is giving evidence, says he will make a point of asking: "Where's Irene?"

On the day Kraft made an offer Cadbury couldn't refuse, Rosenfeld said: "I warmly welcome Cadbury employees into the Kraft Foods family and look forward to meeting many of them in the days and weeks ahead." Six weeks on, her absence from Bournville has been noted by workers. It is said to be at the behest of PR minders who advised against such a trip for the time being, given the level of ill-feeling. "No she has not been to Bournville yet but she is looking forward to it," said a Kraft spokesman.

Kraft's decision to renege on an early promise to grant Somerdale a reprieve has fuelled mistrust of its faceless new US owner in a workforce used to its special brand of "philanthropic capitalism" that dates back to the confectioner's Quaker founders. The pledge, made at the outset of the five-month takeover battle, was designed to win their confidence but is now viewed by union officials as a cynical attempt to manipulate public opinion and mask the Maxwell House-to-Philadelphia-cheese group's reputation for being a rapacious cost-cutter. The Takeover Panel is as keen as the MPs on the business, innovation and skills (BIS) committee to get to the bottom of why Rosenfeld says one thing, only to do another.

"It would be better if Irene Rosenfeld was coming in person but she has decided not to," said Peter Luff, the BIS committee's chairman. "We will be asking Kraft about the past and the future as well as the decision to close Somerdale. It is in their interests for the committee and the wider world to be satisfied by their answers."

Although Rosenfeld frequently flies around the world in the company jet, Kraft has put forward three executives including one of its PR men, Marc Firestone, the executive vice-president for corporate and legal affairs, to face the music. Michael Osanloo, the director of strategy at Kraft who is in charge of integrating Cadbury, will also be absent. "The team we are putting up is best-placed to answer the questions the committee wants answered," said Kraft. "Marc was a core member of the deal team and has day-to-day responsibility for many of the areas it is interested in."

Luff said the committee was not a "one-day wonder" and would not let the matter rest if it felt it had not been told the whole story.

The sour taste left by the takeover battle has fired up Unite to campaign for a "Cadbury law", essentially a public interest test to guard British companies against hostile foreign takeovers. "Kraft deliberately misled workers at Somerdale," said Jennie Formby, Unite national officer for the food and drink sector. "They started to believe their jobs would be safe. It is an outrageous way to treat people and they don't care."

"If Irene doesn't turn up on Tuesday it shows complete disdain for the UK workforce, government and regulatory authorities," she said.

Formby said Kraft had reneged on promises made to the Swedish authorities and workers at chocolate brand Marabou, which it acquired in the early 1990s. "There is a pattern of behaviour where Kraft has taken companies over and then stuck two fingers up."

Lord Mandelson was given no advance warning that Kraft was to break its word on Somerdale and in a recent speech to City bosses he said there was a need to "throw some extra grit" at the country's mergers and acquisitions' regime. The business secretary said directors should be "stewards" rather than just "auctioneers", adding, "if this requires restating the 2006 Companies Act then so be it".

"The open secret of the last two decades is that mergers often fail to create any long-term value, except perhaps for the advisors and those who arbitrage the share price," said Mandelson.

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